Correspondence. 139 
of Algeria; to M. Bonissent for his work on the Geology of the 
Département de la Manche; and to M. Boucher de Perthes for his 
researches on the natural history of man in prehistoric times. A 
gold medal has also been voted by the Society for the Encourage- 
ment of National Industry to M. Alibert, for his discovery of 
Graphite in Siberia, magnificent specimens of which were shown in 
the Great International Exhibition of 1862.*—D. T. A. 
CORRESPONDENCE. 
Se es 
To the Editors of the GEOLOGICAL MAGAZINE. 
Your correspondent Col. Greenwood suggests an enquiry con- 
cerning rainless districts. I believe it is quite certain that the North 
of Africa and the whole of Asia Minor are subject to occasional 
rains, in a certain sense seasonal, though for the most part, and some- 
times for more than one year at a time, in the greater portion of 
these wide tracks no rains fall. At any rate, there are no periodical 
rains; and it is rather in contradistinction to such districts, and to 
distinguish areas where there is no constant precipitation, than as an 
absolute proposition, that the expression is made use of. Col. Green- 
wood is no doubt aware that there are other tracts, especially that 
on the west side of the Andes, where rain is so excessively rare that 
the inhabitants would regard it as almost a miracle. I remember 
being told some years ago by a resident at Alicante, on the east coast 
of Spain, that there had been no rain in that district for more than 
twenty years. Since then there have been rainy seasons, and it is 
probable that small showers may have been forgotten ; but there are 
local conditions in that neighbourhood very,unfavourable to rain. 
Perhaps this explanation will satisfy your readers that it may be 
convenient, and in some sense correct, to call certain large areas 
‘rainless, though rain occasionally falls on parts of them, and in- 
clude others among provinces of autumn- or winter-rains, which are 
as dry as the former. Certainly Canada and Ireland would not be 
incorrectly regarded as excluded from earthquake-districts, though 
a shock now and then may be felt in either country. 
D. T. AnstxEp. 
Impington Hall, Cambridge, August 6, 1864. 
Visit TO SeLtsrty. From Letter, Aug. 8, 1864. 
‘Last week I spent a couple of days (or rather tides) at Selsey in 
examining some of the Quaternary deposits. They are very curious, 
but not easy of interpretation, though I had read Godwin-Austen’s 
paper before going there. I saw the Pholas holes in the Kocene 
beds, a privilece which fortune has seldom if ever granted, I believe, 
* One of the finest specimens of Siberian Graphite brought over by M. Alibert 
is now placed in the British Museum. 
7 Geol. Soc, Journ., vol. xiil. p. 48. 
